Showing papers by "Oregon State University published in 1980"

Stratocumulus-capped mixed layers derived from a three-dimensional model

Abstract: Results of a three-dimensional numerical model are analysed in a study of turbulence and entrainment within mixed layers containing stratocumulus with or without parameterized cloud-top radiative cooling. The model eliminates most of the assumptions invoked in theories of cloud-capped mixed layers, but suffers disadvantages which include poor resolution and large truncation errors in and above the capping inversion. For relatively thick mixed layers with relatively thick capping inversions, the cloud-top radiative cooling is found to be lodged mostly within the capping inversion when the cooling is confined locally to the upper 50 m or less of the cloud. It does not then contribute substantially towards increased buoyancy flux and turbulence within the well mixed layer just below. The optimal means of correlating the entrainment rate, or mixed-layer growth rate, for mixed layers of variable amounts of stratocumulus is found to be through functional dependence upon an overall jump Richardson number, utilizing as scaling velocity the standard deviation of vertical velocity existing at the top of the mixed layer (near the center of the capping inversion). This velocity is found to be a fraction of the generalized convective velocity for the mixed layer as a whole which is greater for cloud-capped mixed layers than for clear mixed layers.

Particulate organic carbon flux in the oceans—surface productivity and oxygen utilization

Abstract: Organic detritus passing from the sea surface through the water column to the sea floor controls nutrient regeneration, fuels benthic life and affects burial of organic carbon in the sediment record1–3. Particle trap systems have enabled the first quantification of this important process. The results suggest that the dominant mechanism of vertical transport is by rapid settling of rare large particles, most likely of faecal pellets or marine snow of the order of >200 μm in diameter, whereas the more frequent small particles have an insignificant role in vertical mass flux4–6. The ultimate source of organic detritus is biological production in surface waters of the oceans. I determine here an empirical relationship that predicts organic carbon flux at any depth in the oceans below the base of the euphotic zone as a function of the mean net primary production rate at the surface and depth-dependent consumption. Such a relationship aids in estimating rates of decay of organic matter in the water column, benthic and water column respiration of oxygen in the deep sea and burial of organic carbon in the sediment record.

A Variable Circular-Plot Method for Estimating Bird Numbers

Abstract: -A bird census method is presented that is designed for tall, structurally complex vegetation types, and rugged terrain. With this method the observer counts all birds seen or heard around a station, and estimates the horizontal distance from the station to each bird. Count periods at stations vary according to the avian community and structural complexity of the vegetation. The density of each species is determined by inspecting a histogram of the number of individuals per unit area in concentric bands of predetermined widths about the stations, choosing the band (with outside radius x) where the density begins to decline, and summing the number of individuals counted within the circle of radius x and dividing by the area (m2). Although all observations beyond radius x are rejected with this procedure, coefficients of detectability may be determined for each species using a standard fixed maximum distance. A bird census technique that estimates the number of birds per area rather than relative abundance is desirable when the objective is to estimate the number and species of birds in a community for energetic considerations (Wiens and Nussbaum 1975), for calculating species diversity (MacArthur 1960, MacArthur and MacArthur 1961), or for elucidating the effects of habitat disturbances on bird populations (Bock and Lynch 1970). Since existing methods require different amounts of effort and give results of differing accuracy (Kendeigh 1944, Emlen 1971, Robinette et al. 1974, Best 1975, Franzreb 1976), the choice of a suitable technique should be based on the species of interest, the season of the year, time and personnel available, number and types of habitats to be censused, and accuracy of the density estimate that is required. Territorial or spot-mapping methods (Williams 1936, Kendeigh 1944) require that the census be conducted during the breeding season and involve considerable time and effort. Both factors severely restrict the number of habitats that can be sampled (Franzreb 1976). Plots of fixed size (e.g., Fowler and McGinnes 1973, Anderson and Shugart 1974), whether traversed by transect or censused from a fixed point, are more easily censused since only bird occurrence needs to be noted. However, density estimates from a number of fixed plots in habitats that differ structurally may not be comparable because of differences in the detectability of birds. For this reason data from fixed plots are frequently reported as relative numbers rather than densities. One way of adjusting for varying detectability among species is to use small plots in dense ,vegetation and large plots in open habitats. Problems arise when an "optimal" plot size, in which the detectability effects are averaged across all species in the community of interest, is required. Another problem is the variance in effectiveness in which two or more observers census plots of fixed sizes (Emlen 1971). Emlen's (1971) variable strip transect count, in which right angle distances from the transect to each observation are estimated, eliminates problems of matching plot size to habitat complexity. This is so because the area used to calculate density is determined by the distance on both sides of the transect within which all individuals of a species are seen or heard. Consequently, the area surveyed is determined by the detectability of each species and observer acuity in each habitat. Additionally, the variable strip method is rapid and relatively accurate and one person can census a variety of communities during any season. For a discussion of these points and a comparison of the variable strip count with the spotmap method see Franzreb (1976). In our work we have found that a stationary observer spends more time searching for birds and less time watching the path of travel. This is particularly true in tall, dense 310 R. T. REYNOLDS, J. M. SCOTT AND R. A. NUSSBAUM vegetation and in uneven terrain. Thus. as " a result of being stationarv. estimates of density and of siecies compbsition should improve. We found, for example, that stationary observers have a greater probability of seeing and hearing birds high in the canopy than even slowly moving observers; standing observers have less effect on bird acGvity; and, because rates of travel along a transect vary with terrain, complexity of vegetation, and number of birds seen, a further advantage of being stationary is that the census periods at each station can be fixed. This aids in standardizing the time spent counting birds in each habitat. Finally, the use of stations allows more definite statements to be made concerning the relationships between the habitat variables and the abundance and occurrence of bird species. This DaDer describes a variable circularplot census technique that gives estimates of birds per unit area during all seasons. This method originated in the need for an effective techniiue for counting birds in mature conifer forests. As such, it represents an a t t em~t to combine what we feel are the best attr;butes of existing methods for habitats of this type. Following its development and use in conifer forests, we have applied it to shrub-steppe, riparian, and semi-tropical rain forests. DESCRIPTION OF THE METHOD In the variable circular-plot method, stations (points) are established within a plant community either at equal intervals along a transect or scattered (avoiding edges) in such a manner as to minimize the probability of observing the same bird from several stations. Thus, the distance between stations depends (in part) on how far away the birds can be detected and how fast they move; it will vary with vegetation and the behavior of the birds (see below). Each bird seen or heard during a fixed time period around a station is counted and the horizontal distance to its location when first observed is estimated. We adjust the time counting at stations to match the structural characteristics of the vegetation and the number of bird species in the plant community being censused. Our strategy is to select the time required to count all birds within an effective detection distance (see below) but to keep the time short enough so that the probability of counting the same bird more than once or of counting birds that move into the area being sampled is minimized. For conifer forests, 10 min at each station following a 1-min "rest period" for equilibration of bird activity after arrival at each station, appears to be sufficient. For the closed canopy rain forests of Hawaii, 8 min is sufficient (J. M. Scott and J. L. Sincock, unpubl, data). For more open habitats (e.g., shrub-steppe) less time is required. With the variable circular-plot method no maximum distance restrictions are placed on any observation. We count only those birds actively using the census area. For example, gulls flying over a stand of cottonwoods are not counted. Peregrine Falcons (Falco peregrinus) soaring over the same area are included because they may capture prey therein. Birds that are flushed while approaching a station are recorded using the distance from the station to where they were first observed as the detection distance. Species that commonly do this are quail, grouse, hawks and owls. In the analysis, we determine the distance from the stations where the number of birds observed begins to decline (the point of inflection) by plotting for each species the number of individuals seen in concentric bands around all stations in each type of habitat. Since the area in each consecutively larger band around the stations is greater (see below) the number of birds observed in each band cannot be plotted directly. Thus, we plot the number of birds per area per band and convert the density in each to a standard of birds/km2. The number of birds in the habitat is then determined by summing the number of individuals counted within the circle of radius x (the inflection point), dividing by the area (,rr2) and converting the resultant density to a standard area (birds/km). With this procedure, we reject all observations outside of the circle of radius x. However, coefficients of detectability (CDs) may be calculated from these data using a standard fixed maximum distance for all species as described by Emlen (1971). For example, we plot the density (birds/ km) of Apapane (Himatione s. sanguinea) in each band with 5-m widths from 0 to 100m, and 10-m widths from 100-m to 200-m from the stations (Fig. 1). Since the density of birds recorded in the bands may vary, we established the following criteria to provide consistency in estimating the point of inflection: choose the distance to the outermost edge of the band where the density of individuals per km2 in the next outermost band is less than 50% of the previous band, with the specified condition that the number of individuals per km in any one of the CIRCULAR-PLOT CENSUS METHOD 311 lnf lect ion Point L

On the Structure and Dynamics of Monthly Mean Sea Level Anomalies along the Pacific Coast of North and South America

Abstract: The behavior and relationship of anomalies of monthly mean sea level, coastal sea surface temperature and alongshore wind stress for the eastern Pacific Ocean during the period 1950–74 have been studied Sea level and temperature records from Yakutat, Alaska (59°N) to Valparaiso, Chile (33°S) and computed alongshore wind stress at near coastal grid points from Yakutat to Matzatlan, Mexico (23°N) have been utilized The positive and negative sea level anomalies, corresponding to El Nino-anti El Nino cycles, are well correlated throughout the tropics of both hemispheres and are detectable at the California stations From Crescent City to Antofagasta, Chile the sea level anomalies were correlated with the Southern Oscillation Index above the 99% significance level The maximum station separations for which sea level anomalies were correlated among themselves above the 99% significance level varied from 6000 km (Yakutat to San Diego) to more than 12 000 km (Prince Rupert to Matarani) A well-defined

Cloud Top Entrainment Instability

Abstract: The criterion for instability of dry air mixing into a cloud top is determined both graphically and mathematically. It is found to be identical to the buoyancy-flux instability criterion of Randall (1976) based on stratocumulus mixed-layer jump-model equations which yield a cloud top jump in θe, for marginal stability of order Δθe=−1 to −3 K (θe), is equivalent potential temperature). Numerical calculations from a three-dimensional boundary-layer turbulence model with stratocumulus are examined from the viewpoint of cloud top entrainment instability. The entrainment rate is found to increase decisively when Δθe, drops below the critical value. The resulting rapid entrainment is found to dry out the cloud from the bottom up, leaving the cloud-base height intact; in conjunction with the negative Δθe value, this causes ∂θe/∂z in the cloud layer to become negative. This in turn sets the stage for the final phase of stratocumulus breakup, whereby conditional instability of the first kind begins to ope...

Attitudes of heterosexuals toward homosexuality: A Likert‐type scale and construct validity

Abstract: This article reports on three phases of the development of a Likert‐type scale measuring heterosexual attitudes toward homosexuality. Phase 1 describes the development of the scale. Item analysis yielded 20 statements with item‐total correlations ranging from .57 to .74. In Phase 2 the 20‐item Heterosexual Attitudes Toward Homosexuality (HATH) Scale was administered to 82 subjects. Analysis yielded a corrected split‐half correlation of .92, and the scale was found to discriminate between individuals based on sex, academic major, and church attendance. In Phase 3 (a validation study) the HATH was administered with several additional attitude scales and indexes of an exploratory nature. Analysis yielded a corrected split‐half correlation of .92. As in Phase 2, a significant effect of sex was found; females appear more tolerant than males. In addition, the HATH correlated significantly with peer attitudes, religiosity, and authoritarianism. The scale has satisfactory reliability and shows promising ...

The monod equation: A revisit and a generalization to product inhibition situations

Abstract: This paper shows how to treat the substrate-limiting Monod equation in a straight forward manner for different types of fermentors (plug-flow, batch, and mixed-flow) using the general language of chemical reaction engineering. Straight-line plots are developed for directly finding the kinetic constants of the equation, and an example using Monod's original data illustrates the procedure. The Monod equation is then generalized to account for the effects of both substrate and inhibitory toxic wastes. Finally, for pure product inhibition performance, expressions are derived for various reactor types, and correlation graphs are developed for finding the kinetic constants of the reaction. An example from the recent literature shows that this equation form fits the data extremely well.

Deposition of submarine crusts rich in manganese and iron

Abstract: The chemical and mineralogical analyses of manganese-rich and iron-rich oxide crusts, of probable hydrothermal origin, from several locations on active spreading centers and seamounts in the Pacific and Atlantic indicate that these crusts originate from a uniform depositional process. These crusts are characterized by extreme Fe/Mn ratios, Fe and Si contents which co-vary, generally very low concentrations of most trace metals and the rare-earth elements, and variable contents of Zn and the volatile elements Hg, As, and Sb. Co is markedly depleted relative to Cu and Ni, and Zn is enriched, resulting in characteristically low Co/Zn values. These compositions can be accounted for by the fractional precipitation of Fe, SiO 2 , and Mn and incorporation of Zn, As, Sb, and Hg from hydrothermal solutions, and adsorption of minor amounts of Co, Cu, Ni, Pb, Ba, and rare-earth elements from sea water. Mineralogical analyses by ultra-slow scan X-ray diffraction show the manganese-rich crusts to be composed of nearly pure, well-crystallized birnessite and/or todorokite. Iron-rich crusts consist of either amorphous hydrated iron oxide and silica or iron-rich, low-aluminum nontronite. Analyses of a suite of thin ferromanganese crusts formed on ocean-ridge out-croppings of basalt and of a number of Pacific manganese nodules indicate that ferromanganese crusts are enriched in Fe and Si and depleted in trace metals relative to nodules and are similar in chemical composition to East Pacific Rise metalliferous sediments. The similarity of the ferromanganese crusts to metalliferous sediment suggests that they have a common origin. It is believed that most of the Fe, SiO 2 and Mn entering sea water in hydrothermal solutions precipitates as colloidal SiO 2 and hydrated Fe and Mn oxides which are advected by bottom currents and deposited as crusts and sediments. Trace-element contents in these deposits result from adsorption from sea water onto the Fe and Mn colloids during advection.

Laboratory studies of the entrainment zone of a convectively mixed layer

Abstract: In laboratory experiments of simulated atmospheric mixed layers the entrainment zone is investigated from measurements of horizontally averaged temperature and buoyancy flux, and from visual observations of penetrating thermals using a spread laser beam. The region of negative buoyancy flux of entrainment is found to be confined between the outermost height reached by the few most vigorous penetrating parcels, and by the lesser height where mixed-layer fluid occupies, usually, some 90 to 95% of the total area. The height of most negative buoyancy flux of entrainment is found to agree roughly with the level at which mixed-layer fluid occupies half the area.The thickness of the entrainment zone, relative to the depth of the well-mixed layer just beneath, is found to be quite substantial (0·2 to 0·4), and apparently decreases only asymptotically with increasing ‘overall’ Richardson number, Ri*. The thickness is not well predicted by parcel theory.Extensive detrainment is found to occur within the entrainment zone, and adds to the difficulty in defining the position of the local interface between mixed-layer fluid and unmodified fluid.For typical Ri* values occurring in the atmosphere, the dimensionless entrainment rate is found to be given satisfactorily by 0·25(Ri*)−1, although an dependence cannot be ruled out by the present data. Entrainment into a neutral layer in the absence of a capping inversion is found to proceed at the expected rate.

Intrusion of basaltic sills into highly porous sediments, and resulting hydrothermal activity

Abstract: Sill intrusions into highly porous sediments in the Guaymas Basin, Gulf of California, lead to low-grade metamorphism, thermal alteration and migration of organic compounds, marked changes in interstitial water chemistry, and large-scale expulsion of heated pore fluids. The latter process creates space for the intruding magma and initiates a hydrothermal system, which can explain the observed hydrothermal deposits around fault scarps on the basin floor.

The Agulhas Current During the Late Pleistocene: Analysis of Modern Faunal Analogs

Abstract: Analysis of micropaleontologic evidence in a deep-sea core in the south-west Indian Ocean indicates that the Agulhas Current was not a dominant feature of this region during glacial intervals. Interpretation of the fossil record, based on the analysis of modern faunal analogs, indicates that during glacial intervals the Agulhas Current was not the strong, year-round current that it is today. Evidence shows that during summer months a weak tropical current was present. During winter months the current was replaced by cool, high-salinity waters. This interpretation suggests that seasonal changes in circulation may have been more pronounced in the southwest Indian Ocean during glacial intervals than today.

A new high pressure equation of state for seawater

Abstract: A new high pressure equation of state for water and seawater has been derived from the experimental results of Millero and coworkers in Miami and Bradshaw and Schleicher in Woods Hole The form of the equation of state is a second degree secant bulk modulus K = Pv0(v0−vp=K0+AP+BP2 K = Kw0+aS+bS32 A = Aw+cS+dS32 B = Bw+eS where ν0 and νP are the specific volume at 0 and P applied pressure and S is the salinity (ℵ) The coefficients KWO, AW, and BW for the pure water part of the equation are polynomial functions of temperature The standard error of the pure water equation of state is 43 × 10−6 cm3 g−1 in νWP The temperature dependent parameters a, b, c, d, and e have been determined from the high pressure measurements on seawater The overall standard error of the seawater equation of state is 90 × 10−6 cm3 g−1 in νP Over the oceanic ranges of temperature, pressure, and salinity the standard error is 50 × 10−6 cm3 g−1 in νP This new high pressure equation of state has recently (1979) been recommended by the UNESCO Joint Panel on Oceanographic Tables and Standards for use by the oceanographic community

Factors affecting spore germination of the vesicular-arbuscular mycorrhizal fungus, Glomus epigaeus.

Abstract: Soil moisture, temperature, and—to a lesser degree—pH influenced germination of Glomus epigaeus spores, whereas levels of soil fertility and spore density had little or no effect. Maximum germinati...

Stem growth per unit of leaf area: a measure of tree vigor.

Abstract: The ratio of basal area growth to sapwood basal area is shown to correspond with stemwood-volume production per unit of leaf area. Analyzing 122 healthy Douglas-fir in one stand showed this ratio to be consistent among all but suppressed trees. Evaluating other stands suggests the ratio may be sensitive to environment and reflect competition. This ratio of tree vigor will aid silviculturists in determining optimum stocking or in maintaining a stand at a selected level of vigor. FOREST SCl. 26:112-117.

Stress and Social Hierarchy Rank in Coho Salmon

Abstract: Dominance hierarchy was monitored over a 2-week period in triplicated groups of six parr of coho salmon (Oncorhynchus kisutch) by recording a variety of behavioral activities. Indices of stress were subsequently determined and compared with dominance statuses. Social position fell into three main categories: (1) the dominant fish; (2) two or three intermediate fish; and (3) two or three subordinate fish. Plasma cortisol concentration, interrenal nuclear diameter, and tail-beat frequency were lowest in the dominant fish and highest in the subordinate fish. Fish held alone had levels of plasma cortisol, interrenal nuclear size, and tail-beat frequency similar to those of the dominant fish. Hepatic glycogen varied directly with social position. It is plausible that dominance status is inversely related to a low-level, chronic state of stress in the fish, the dominant individuals being the least stressed.

Some effects of douglas fir terpenes on certain microorganisms.

Abstract: The Douglas fir terpene α-pinene was shown to inhibit the growth of a variety of bacteria and a yeast. Other terpenes of the Douglas fir, including limonene, camphene, and isobornyl acetate, were also inhibitory to Bacillus thuringiensis. All terpenes were inhibitory at concentrations normally present in the fir needle diet of Douglas fir tussock moth larvae. The presence of such terpenes in the diet of these insects was found to strongly influence the infectivity of B. thuringiensis spores for the Douglas fir tussock moth larvae. The terpene α-pinene destroyed the cellular integrity and modified mitochondrial activity in certain microorganisms.

Transcription in Isolated Wheat Nuclei: I. ISOLATION OF NUCLEI AND ELIMINATION OF ENDOGENOUS RIBONUCLEASE ACTIVITY

Abstract: Nuclei isolated from embryos of wheat (var. Yamhill) incorporated [3H]UTP into a trichloroacetic acid-insoluble product linearly for 60 minutes. When the RNA synthesized in vitro was analyzed on a sucrose gradient, the amount of RNA in the 4S region increased with longer incubation times. These data and the absence of higher molecular weight RNA of specific size classes in our work (and previously published reports) suggested that nuclear fractions from plant tissue contained active nucleases. This was confirmed when wheat nuclei were mixed with [3H]yeast RNA (4, 18, 26S). All of the radioactive yeast RNA was degraded within 30 minutes to species sedimenting between 4 and 10S. The inclusion of high salt (125 millimolar (NH4)2SO4, 100 millimolar KCl), EGTA, and exogenous RNA or DNA reduced but did not eliminate endogenous RNase activity. Wheat embryo nuclei were further purified by centrifugation on a gradient of a polyvinylpyrrolidone-coated colloidal silica suspension (Percoll). These nuclei were ellipsoidal, free of cytoplasmic material, and lacked endogenous nuclease activity when assayed with [3H]yeast RNA. Sucrose gradients were not as effective as Percoll gradients in purifying nuclei free of RNase activity. The Percoll method of isolating nuclei and the RNase assay reported here will be useful in isolating plant nuclei that are capable of synthesizing distinct RNA species in vitro.

Processing of confined and naturally entrained leaf litter in a woodland stream ecosystem1

Abstract: A comparison between stream community processing rates of naturally entrained leaf litter and leaves in packs or 1 mm-mesh bags demonstrated that packs served as a suitable analogue of processing in exposed sites (riffles) whereas bags did not. In riffles, leaves in bags were processed at rates characteristic of litter in depositional zones (pools and alcoves). A length-weight regression method for evaluating the range of microhabitat-related processing rates in stream communities appears suitable. Leaf litter nitrogen levels and increased processing rates by shredders reflected microbial conditioning. Shredders responded to high quality basswood (Tilia americana) leaves by increasing their density rather than growth per individual.

A field investigation of the relationship between oscillation ripple spacinng and the near-bottom water orbital motions

Abstract: Measurements of oscillation ripples have been obtained in the high-energy wave environment off the Oregon coast, and in the relatively mild summer-wave environment near Fisher's Island, New York. Scuba-equipped divers measured ripple characteristics while the simultaneous causative near-bottom orbital motions were determined from a wave pressure transducer and electromagnetic current meter mounted near the bottom. The data collected in this study, together with previously published field measurements of oscillation ripples, are compared with empirical relationships for ripple geometry based on laboratory data. As expected, the field data are more scattered than the laboratory data. Reasons for this scatter include several wave spectral effects, ocean waves in the study areas having wi e spectra in contrast to the simple harmonic motions of the laboratory devices. Any selected trend that relates the ripple spacing to the wave orbital motions must take into consideration this spectrum and the manner in which the orbital parameters are defined. Orbital parameters calculated from a significant wave height were found to give the best comparison with the laboratory results.